There are several ways to differentiate pleural pericardial effusions. This video goes over one method using a parasteral long axis view. It highlights some anatomy that isn’t always mentioned when reviewing echocardiography texts.

Plus it allowed me to test drive a new program called Doodlecast Pro. Let me know what you think for this format.

This research letter is published online ahead of print in the American Journal of Emergency Medicine.  It reviews some of the Twitter statistics from the American College of Emergency Physicians 2010 Scientific Assembly and the Society for Academic Emergency Medicine 2011 Annual meeting.

It also raises the idea of the metric of individual user, original tweets, and original tweet per individual user for evaluating Twitter volume during conferences.

The citation and a pre-production pdf version for those who do not have journal access is: Nomura JT, Genes N, Bollinger HR, Bollinger M, Reed JF 3^rd. Twitter Use During Emergency Medicine Conferences. Am J Emerg Med. Epub ahead of print. PMID 22424992.

This is an expanded version of the table with data points that were not included in the letter due to some requested edits and length.

SAEM Social Media Committee Video Conference

Short video conference discussing the upcoming didactic session at the Society for Academic Emergency Medicine on Social Media and the Academic Physician at the 2012 Annual Meeting.

**This post was originally part of the ACEP Emergency Ultrasound Section’s Newletter in the Tips and Tricks section . The newsletter is located on the member only section of the site so I am posting here to make it more available.**

Patients commonly present with complaints of abdominal hernias and are frequent incidental findings in the emergency department. Incarcerated hernias can cause swelling, pain, and may require emergent surgical consultation if strangulated.

While an incarcerated hernia can be found on physical exam, ultrasound can assist in the management of these cases. Imaging the incarcerated hernia to identify the contents of hernia sac can help differentiate bowel from adipose tissue. As well, one can identify concomitant pathology such as free fluid, bowel wall thickening, pneumotosis coli, aperistalsis, and abnormal blood flow.

Diagnostic imaging is commonly described in many texts and articles; however, an additional step in the imaging protocol can help with the management of incarcerated hernias. Scan through the hernia sac and pay special attention to the abdominal wall for the break in the wall or the neck of hernia sac, this will allow planning for reduction. Identification of the neck allows the operator to direct the hernia contents toward the neck during manual reduction. It also allows the clinician to identify the size of the neck compared to the hernia contents.

Figure 1 shows an incarcerated ventral hernia containing small bowel. The neck can be identified by the defect in the abdominal wall. This hernia was successfully reduced by applying pressure from the lateral edge of the bowel loop toward the neck. Figure 2 shows the hernia post reduction containing only fat; the fascial defect is still visible.

While this large hernia had a midline neck, that is not always the case as demonstrated in Figure 3. The neck is visible and the hernia sac is laterally located. Evaluation of the hernia contents and neck location can aid in planning the reduction. Practice visualizing known hernias and the fascial defect or neck on patients with hernias that are not incarcerated or strangulated.

Figure 1: Incarcerated hernia with bowel and neck visualized.

Figure 2: Post reduction the fat containing hernia and neck are visualized.

Figure 3: Small hernia sac that is lateral to the neck.

It took me a little bit of time to get this collated and together for posting but here it is.

It was a great Scientific Assembly this year in San Francisco.  I have noticed some drift over the last couple of years for me personally when I am at ACEP.  There are more section meetings, committee meetings, and other duties that I have to attend to that reduce the number of didactic presentations that I am able to be at and sufficiently focus enough to live tweet compared to other meetings.

The highlight of the meeting was running into people who I have interacted with on Twitter.  Some people I had already met and knew in real life, but hanging out was fun. We are a very interesting crowd, but all of us are in EM so that is somewhat to be expected.

Dinner was set up by @poisonreview and I got to hang out with @drsamko, @gruntdoc (with wife), @grahamwalker, @M_Lin, @apousson, @nickgenes, @movingmeat, @emcrit, @EMDocBrett, @medgadget, and @DrRWinters.

Here is a pdf of all the #SA11 tweets I was able to gather in reverse chronological order.  There is probably around 1,870 tweets (10 per page and 187 pages); wow.

This month Mike Blaivas and Srikar Adhikari published a case series in JUM on soft tissue ultrasound of abscess where there were unexpected findings (Unexpected Findings on Point-of-Care Superficial Ultrasound Imaging Before Incision and Drainage JUM Oct 2011;30:1425-1430).

This Case Review goes through some video clips of similar cases and the “streaming” effect you can see with an abscess.

Click on the Image to play the video.

There was a recent manuscript that came across my desk from the medical journal Medical Ultrasonography. This is a peer reviewed Medline indexed journal. The publication caught my attention because it discussed using a sagittal vessel view with in-plane needle guidance (long axis) vs transverse vessel view and out-of-plane needle guidance (short axis). The article is available online in full text at Medical Ultrasonography.

This article was interesting in that they concluded that experienced users (anesthesia) had better first pass success and less carotid puncture using the short axis compared to the long axis. This seems a bit counter-intuitive. A method where the needle tip is not visualized directly was associated with better success and less complications?

There are a few things to note about this study and the methods. First short axis success was defined as aspiration of blood and visualization of “indentation of the anterior wall”. While success for the long axis was defined as visualizing the needle enter the vein. The different methods has different measures of success. The needle tip could have been as easily confirmed within the vessel lumen in the short axis as it was for the long axis rather then the surrogate marker of vessel wall deformity and blood aspiration.

Secondly the authors also state that “The operators in our study have less experience in long axis cannulation than short axis cannulation because the long axis cannulation needs more hand eye coordination and alignment of the probe than short axis approach.”  I agree with this statement.  The long axis is a more technically difficult method and requires more experience, skill, and attention to detail.  However, if the operators were not as skilled in the long axis does this study really evaluate long vs short or merely the operator’s skill with each technique?

There was also no mention of frequency of posterior or deep wall punctures and possible resultant hematomas.  There were 2 carotid punctures (non-significant) in the long axis group, but not a clear discussion of the reasons leading up to accidental punctures.  Was that a failure of the technique or operator error?

In the end this article is interesting but does not answer the question of long vs short axis for me.  The limitations of the study make drawing practice changing conclusions difficult.  I personally prefer the long axis technique to visualize the needle and its movement during realtime with relation to the vessel and the posterior wall.

In the end it shows that ultrasound is a tool and technique and experience is important, or as Masharu Morimoto once said (world renowned chef), “my knife is sharp, but my arm is sharper”.  Referencing that his knives are important but his skill and technique is more important.

This is a case of some subtle findings during the pelvis view of a FAST exam.  There is also a short discussion of why the image can appear different based upon ultrasound physics.  This has only video rather then flash so iPad users can enjoy too.

Click on the image to play the video.

On this blog I have been creating either Flash based modules, videos, or posts with still images.  All of these methods are asynchronous eLearning examples.  Meaning that the learner doesn’t is seeing it at the same time that it is being performed or created.  With the use of high bandwidth internet access and newer technologies you can also have synchronous eLearning opportunities.  This means that the interaction between learner and instructor is going on at the same time.

Utilizing video conferencing software learners and instructors can be connected in realtime for a presentation and also have the ability for interaction and discussion.

I work with Emergency Ultrasound Consultants who have the Virtual Ultrasound Director program.  This provides monthly feed back on Emergency Ultrasounds that are performed at an ED in this interactive synchronous eLearning environment.  Below is a short video clip of a VUD session.  The nice thing of using some of these video conference options (Adobe Connect in this case) is the ability to record a session to produce an asynchronous eLearning module for learners who could not be present.

This is a short recording excerpt from a session reviewing the RUQ in the FAST exam.  What is not seen is the participant list and chat box to preserve the participant anonymity.  Some of the pauses to allow participant interactions are also removed for your viewing pleasure.

Click on the image below to view the video.

This is a short article that my colleagues and I wrote for the American College of Emergency Medicine Emergency Medicine Ultrasound Section April Newsletter.

The full newsletter can be found here.

The Focused Assessment with Sonography in Trauma or FAST exam is one of the most common Point of Care Ultrasound exams performed in the Emergency Department.  As discussed in numerous forums, the FAST (or E-FAST) exam can be used in multiple clinical scenarios beyond the traumatically injured patient.  We will discuss two common errors that can lead to the misdiagnosis of subtle findings.

The pelvic windows in the FAST exam are often scanned hastily if the RUQ and LUQ do not show free fluid; however, subtle pathology can be missed if the windows are not surveyed in a thorough manner.

The urine-filled bladder results in posterior acoustic enhancement, which can obscure pelvic structures and pathology posterior to the bladder.  This will be amplified if the far field gain is not appropriately adjusted.  Structures may appear significantly more hyperechoic, and free fluid can be missed due to wash-out from an overgained far field image.  Figure 1 is an example of missed pelvic free fluid due to posterior acoustic enhancement.  The overgained far field obscures the free fluid.

Figure 1:  Sagittal view of the bladder with free fluid.  The posterior acoustic enhancement leads to an overgained far field despite the appropriate gain settings of the near field.  This small amount of free fluid, caused by a liver injury, was missed on initial evaluation.

Figure 2 demonstrates a similar transverse view of the bladder, but with improved far field gain.  Internal echoes are visible within the free fluid due to posterior acoustic enhancement; however, further reduction in far field gain may reduce visualization of anatomic structures.  Sonographers must strike a balance between adjusting the far field gain to adequately visualize free fluid while still identifying posterior structures and boundaries.  This highlights the need to remain vigilant in looking for small amounts of free fluid or other subtle findings.  Despite the reduced far field gain and improved image, the persistent artifact within the fluid could mask this pathology.  Appropriate imaging and assessment in the suprapubic window requires an understanding of both the pitfalls of posterior acoustic enhancement, as well as any limitations that can be encountered when correcting for this artifact.

Figure 2:  Sagittal view of the bladder with subtle free fluid.  Although the far field gain is better than Figure 1, there are still echoes within the free fluid due to posterior acoustic enhancement.  This highlights the need to be vigilant for subtle findings in the FAST exam.

The second common error occurs while imaging the bladder in the transverse plane.   Sonographers commonly fail to adequately visualize the lateral edges of the structure.  One of the goals of transverse imaging is to evaluate for free fluid that is lateral to the bladder and may not be apparent on sagittal imaging.  Figure 3 demonstrates this potential pitfall.

Figure 3:  Transverse view of the bladder with free fluid located laterally to the bladder.

Figure 4 shows a transverse view in which the lateral edges are not visualized.  This occurs most commonly either when the bladder is distended or when a small footprint transducer, such as the phased array or small curved array, is used.  If this occurs, the lateral edges need to be evaluated by scanning each half of the bladder separately on transverse imaging.

Figure 4:  Transverse image of the bladder using a phased array transducer.  Due to the small footprint, the lateral edges of the bladder are not visualized and free fluid may not be visualized.